There are lots of silly rules in gardening but the one I hate most says you can only divide perennials at certain times of the year.
I have two rules:

  1. Don?t do it if there?s going to be a frost next week;
  2. And not during a heat wave.

There are good reasons for dividing plants:

  • To fill up holes all around the garden,
  • To make a new more felicitous combinations
  • To rejuvenate old plants and make them look young again as the word implies.

The other day a friend (and you will need one) and I whacked gigantic hostas in halves and thirds. I intended to do this in spring but there was too much going on. Better to do it when it?s fun, if you call digging up 50-kilo hostas fun.? They are hard to divide in full summer growth but what a huge difference in how they look for the rest of the year (richer, silkier leaves).

They tend to sulk for a couple of days but bounce back amazingly well. The new plants you create by division are incredible because they are large, well-grown and will flourish very quickly in a new location.
To divide big heavy plants use a transplanting spade to lift them out of the ground. Then get a garden spade with a flat sharp edge and whack the plant in the middle as hard as you can. Choke back all those empathetic feelings. If leaves break off, put them in a vase. In fact, almost all foliage looks fabulous in a vase, especially hostas.

Have a hole at the ready and make it exactly the size as the chunk you are taking out of the ground. Fill it with water to make sure the drainage is good, and then plop the division into place and back fill.? Don?t amend the soil. This is where the plant has to live. So tough love is the order of the day. But water thoroughly so it flows below the root system and then add some compost around the top of the soil. For the next two weeks keep your eye on the new plant and make sure it?s watered deeply.